Profiled sputtering target and method of making the same

Abstract

A sputtering target comprising a sputtering material and having a non-planar sputtering surface prior to erosion by use in a sputtering system, the non-planar sputtering surface having a circular shape and comprising a central axis region including a concave curvature feature at the central axis region. The central axis region having a wear profile after erosion by use in a sputtering system for at least 1000 kWhrs including a protuberance including a first outer circumferential wear surface having a first slope. A reference, protruding convex curvature feature for a reference target after sputtering use for the same time includes a second outer circumferential wear surface having a second slope. The protuberance provides a sputtered target having reduced shadowing relative to the reference, protruding convex curvature feature, wherein the first slope is less steep than a second slope.

The invention claimed is: 
     
       1. A sputtering target comprising a sputtering material having a non-planar sputtering surface prior to erosion by use in a sputtering system, the non-planar sputtering surface having a circular shape and comprising:
 a central axis region having a center axis; the central axis region including at least one non-protruding concave curvature feature symmetrically disposed about the center axis, wherein a bottom surface of the at least one non-protruding concave curvature feature has a convex shape and the convex shape having a first point on the center axis; and 
 a surrounding region disposed about the central axis region, the surrounding region comprising a top planar surface and at least one recessed groove, wherein the first point is below the top planar surface of the surrounding region, and a bottom-most surface of the bottom surface of the at least one non-protruding concave curvature feature is below a bottom surface of the at least one recessed groove; 
 wherein a distance from the top planar surface of the surrounding region to the first point is about 15 percent to about 30 percent of a total thickness of the sputtering target, and the at least one non-protruding concave curvature feature extends radially from the center axis a radial distance of from about 5 percent to about 40 percent relative to a total radius of the sputtering target. 
 
     
     
       2. The sputtering target of  claim 1 , wherein the sputtering material includes at least one material chosen from Ti, Al, Cu, Ta, Ni, Co, Mo, Au, Ag, Pt, W, Cr, a Ti alloy, an Al alloy, a Cu alloy, a Ta alloy, a Ni alloy, a Co alloy, a Mo alloy, a Au alloy, a Ag alloy, a Pt alloy, a W alloy, and a Cr alloy. 
     
     
       3. The sputtering target of  claim 1 , wherein the least one non-protruding concave curvature feature extends radially from the center axis the radial distance of from about 20 percent to about 30 percent relative to the total radius of the sputtering target. 
     
     
       4. The sputtering target of  claim 1 , wherein the at least one non-protruding concave curvature feature extends radially from the center axis the radial distance of from about 23 percent to about 27 percent relative to the total radius of the sputtering target. 
     
     
       5. The sputtering target of  claim 1 , wherein the distance from the top planar surface of the surrounding region to at the first point is about 15 percent to about 20 percent of the total thickness of the sputtering target. 
     
     
       6. A sputtering assembly comprising:
 a backing plate; and 
 the sputtering target according to  claim 1  bonded to the backing plate. 
 
     
     
       7. The sputtering assembly of  claim 6 , wherein the sputtering target is diffusion bonded to the backing plate.